1. Field of the Invention
This invention relates generally to a downward illumination assembly for directing light downward from a ceiling.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
It is known for a ceiling lamp to be supported above a ceiling panel, and to radiate light downward through an opening formed in the ceiling panel. In passenger elevator applications, ceiling lamps can be supported on the relatively rigid and structurally substantial steel or wood composite drop ceilings that are commonly incorporated into such structures. Because elevators generally include steel shells that are only approximately eight feet tall, the drop ceiling panels are suspended only approximately six inches below top panels of the steel elevator shells. This limits options for servicing components of elevator ceiling lamps, such as ballasts, lamp sockets and associated wiring, that are not accessible from below the ceiling panel of an elevator.
For example, U.S. Pat. No. 5,145,247 issued 8 Sep. 1992 to Mandy, discloses a downward illumination assembly for a passenger elevator. The assembly includes a lamp housing having a closed upper end and an open lower end disposed axially opposite the closed upper end. A tubular canister extends from around a periphery of the upper end, a lower end of the canister defining the open lower end of the housing. Two ceiling mount tabs extend radially outward from diametrically opposite positions on an outer surface of the canister. The ceiling mount tabs provide an engagement surface for screw fasteners connecting the lamp housing to an upper surface of an elevator ceiling panel, holding the canister in alignment with a hole formed in the ceiling panel for the downward passage of light. Two fluorescent lamp tubes are removably supported in respective lamp sockets supported within the lamp housing. A generally tubular trim bezel is friction fit within the tubular canister and is retained, at least in part, by spring clips supported on an inner surface of the canister. A side conduit fitting is aligned with a through hole in the canister and is supported on and extends radially outward from the canister to provide access to the lamp sockets for electrical wires. To service the ballast, lamp socket, or associated wiring, maintenance personnel must unfasten and lower the ceiling panel to gain access to those components. This is because the assembly is mounted on top of the ceiling panel and cannot easily be removed or manipulated from below through the opening formed in the ceiling panel.
What is needed is a downward illumination lamp that can be supported above a ceiling panel in a position to direct light downward through an opening in the ceiling panel while allowing for removal of lamp socket and ballast without requiring removal of the lamp housing. What is also needed is such an assembly that is easy to install on ceiling panels of varying thicknesses.